1. Technical Field
This invention relates generally to bioimpedance measuring systems and in particular to alternating electrode measuring systems for monitoring tissue.
2. Description of the Related Art
Tissue ischemia, a low oxygen state usually due to the obstruction of arterial blood supply or inadequate blood flow leading to hypoxia in tissue, has been widely reported as a cause of gastrointestinal anastomotic breakdown and leakage. Anastomotic leaks are especially prevalent and harmful in the esophagus and in the colon. Gastrointestinal tissue most vulnerable to ischemic conditions is the mucosal tissue on the surface of the intestinal lumen. The mucosal layer is the first tissue layer to show cell death and necrosis when perfusion is insufficient.
Impedance spectroscopy involves multiple measurements over a range of frequencies that provide information about the structural and electrical properties of a sample. Bioimpedance spectrum measurements involve measuring the electrical impedance of tissue to signals of different frequencies. Bioimpedance measurement systems use a number of different electrode configurations to measure tissue damage.
It would be advantageous to provide a system for monitoring the state of anastomosed tissue quickly, easily, and directly. The information provided would alert surgeons to conditions that precede or are associated with anastomotic breakdown and leakage. Having been alerted to impending complications, the surgeons could change their course of treatment to address the developing complication.